1. Field of the Invention
The present invention relates to a battery charging system for an electric vehicle, which enables battery charge in an emergency without authentication and search for a stolen vehicle.
2. Description of the Related Art
Japanese Patent Unexamined Application, First Publication No. 2006-262570 discloses an example of a conventional battery charging system for electric vehicles. In the conventional battery charging system, a battery unit having a battery to supply electric power to an electric vehicle is connected to a charger for supplying electric power to the battery through a power cable. If the power cable of the battery unit is connected to the battery unit, a charge control unit included in the charger controls a power supplying unit to supply power to the battery unit and receives user information by PLC (power line communication) through the power cable for authentication. If the authentication succeeds, the charge control unit measures the amount of charged power and charges for the charged power. If the authentication fails, the control unit terminates the power supply by the power supplying unit.
However, a first problem of the conventional technology is in that a battery is not charged in an emergency if authentication fails. The reason is that the power supplying unit is controlled based only on success or failure of authentication.
A second problem is in that a stolen car cannot be searched if a battery thereof is successfully charged since the authentication result is used only for termination of power supply by the power supplying unit, measurement of charged power, and charge for the measured power.